BOSTON — The final possession of Celtics games earlier this season were a study in sloppiness.

Blown plays, subpar looks, questionable ball-handling and one ever-present question: Who would take the last shot?

Ever since Paul Pierce packed his bags and headed to Brooklyn two summers ago, the Celtics had no real answer to that one.

But now, the Celtics have a player who not only is capable of producing in crunch time, but also embraces the pressure — enjoys it, even. That would be point guard Isaiah Thomas, who in four games has been the go-to guy Boston has sorely lacked since the days of the Big Three.

Thomas has been everything the Celtics could have asked for since Danny Ainge plucked him from Phoenix at the trade deadline. Boston is 3-1 since his debut (3-0 in games Thomas hasn’t been ejected from), and Thomas has been the team’s leading scorer, averaging 22.3 points per game despite playing in a reserve role.

Every hot streak is bound to come to an end eventually, though, and for nearly three quarters of Friday night’s 106-98 win over the Charlotte Hornets, Thomas appeared to have reached it. The diminutive guard had found the bottom of the basket on just three of his first 10 field-goal attempts, and with 10 minutes elapsed in the third quarter, he’d gotten to the foul line — a specialty of his — just twice.

Then, something changed. A switch flipped. To borrow a line from Dustin Pedroia, Thomas turned on the Laser Show.

Thomas scored the final seven points in the third quarter — his only points in the frame — to cut Boston’s deficit from 11 points to four. That barrage continued into the fourth. A 3-pointer at the 8:48 mark tied the game at 80 apiece. A layup on Boston’s next possession pulled the Celtics even again, 82-82.

Thomas missed a layup three minutes later that would have put the Celtics C ahead, but Jonas Jerebko gathered the rebound and canned a jumper. Boston never trailed again.

By the time the final buzzer sounded, Thomas had racked up 14 fourth-quarter points to bring his game total to a team- and season-high 28.

It was the kind of late-game production the Celtics have come to expect from their newest star. Over his last three games (excluding his ejection-shortened debut), 61.8 percent of Thomas’ points have come in the second half, and 42.6 percent have come in the fourth quarter. And that’s not to mention the fact that over those three contests, Thomas has posted an absurd plus-62 plus/minus rating.

“He’s so good at attacking the basket,” Jerebko said after Friday’s win, “and everyone is going to shrink in and find open shooters. And if they don’t, he’s going to try and finish. He’s a great player, and we’re just trying to play off of him.”

The attention Thomas draws has paid huge dividends for his teammates — Jerebko and Jae Crowder, in particular. Jerebko has scored 36 points over the last two games and Friday recorded his first double-double (16 points, 10 rebounds) since 2011, and Crowder’s 16.5 point-per-game average since Thomas’ arrival is nearly triple his season average (6.1).

“That’s pretty nice, but its not me,” Thomas said of the praise he’s received from teammates. “It’s this team. We’re playing hard, coach (Brad Stevens) is putting us in position to be successful and that’s the big key. We are believing in each other.”

The Celtics haven’t found themselves in a position to try a game-winning buzzer-beater since Thomas came to town. But if and when they do, it’s pretty obvious who they’d want taking that shot.